The Southern African Territories (SAT)‐type foot‐and‐mouth disease viruses (FMDV) are endemic to the greater Kruger National Park (KNP) area in South Africa, where they are maintained through persistent infections in African buffalo. The occurrence of FMDV within the Greater KNP area constitutes a continual threat to the livestock industry. To expand on knowledge of FMDV diversity, the genetic and antigenic relatedness of SAT2‐type viruses isolated from cattle during a FMD outbreak in Mpumalanga Province in 2013 and 2014 were investigated. Cattle from twelve diptanks tested positive on polymerase chain reaction (PCR), and molecular epidemiological relationships of the viruses were determined by VP1 sequencing. Phylogenetic analysis of the SAT2 viruses from the FMD outbreak in Mpumalanga in 2013/2014 revealed their genetic relatedness to other SAT2 isolates from topotype I (South Africa, Zimbabwe and Mozambique), albeit genetically distinct from previous South African outbreak viruses (2011 and 2012) from the same topotype. The fifteen SAT2 field isolates clustered into a novel genotype with ≥98.7% nucleotide identity. High neutralization antibody titres were observed for four 2013/2014 outbreak viruses tested against the SAT2 reference antisera representative of viruses isolated from cattle and buffalo from South Africa (topotype I) and Zimbabwe (topotype II). Comparison of the antigenic relationship (r₁ values) of the outbreak viruses with reference antisera indicated a good vaccine match with 90% of r₁ values > 0.3. The r₁ values for the 2013/2014 outbreak viruses were 0.4 and above for the three South African vaccine/reference strains. These results confirm the presence of genetic and antigenic variability in SAT2 viruses and suggest the emergence of new variants at the wildlife–livestock interface in South Africa. Continuous characterization of field viruses should be performed to identify new virus strains as epidemiological surveillance to improve vaccination efforts.

中文翻译：

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南非野生动植物与牲畜交界处SAT2口蹄疫2013/2014暴发病毒的特征分析。

南部非洲领土（SAT）型口蹄疫病毒（FMDV）在南非更大的克鲁格国家公园（KNP）地区特有，通过非洲水牛的持续感染得以维持。大国民党地区内发生口蹄疫病毒对畜牧业构成持续威胁。为了扩大对FMDV多样性的了解，调查了2013年和2014年姆普马兰加省口蹄疫爆发期间从牛身上分离的SAT2型病毒的遗传和抗原相关性。来自十二个双罐的牛经聚合酶链反应（PCR）检测为阳性，并通过VP1测序确定了病毒的分子流行病学关系。对2013/2014年姆普马兰加口蹄疫暴发中SAT2病毒的系统进化分析表明，它们与其他I型拓扑结构的SAT2分离株（南非，津巴布韦和莫桑比克）具有遗传相关性，尽管其遗传学不同于先前的南非暴发病毒（2011和2012年）来自相同的原型。十五个SAT2场隔离群聚成一个具有≥98.7％核苷酸同一性的新基因型。观察到四种针对SAT2参考抗血清测试的2013/2014暴发病毒的高中和抗体滴度，这些病毒代表了从南非（拓扑I）和津巴布韦（拓扑II）的牛和水牛中分离出的病毒。抗原关系比较（r 尽管从基因上与以前的南非暴发病毒（2011年和2012年）在同一拓扑上不同。十五个SAT2场隔离群聚成一个具有≥98.7％核苷酸同一性的新基因型。观察到四种针对SAT2参考抗血清测试的2013/2014暴发病毒的高中和抗体滴度，这些病毒代表了从南非（拓扑I）和津巴布韦（拓扑II）的牛和水牛中分离出的病毒。抗原关系比较（r 尽管从基因上与以前的南非暴发病毒（2011年和2012年）在同一拓扑上不同。十五个SAT2场隔离群聚成一个具有≥98.7％核苷酸同一性的新基因型。观察到四种针对SAT2参考抗血清测试的2013/2014暴发病毒的高中和抗体滴度，这些病毒代表了从南非（拓扑I）和津巴布韦（拓扑II）的牛和水牛中分离出的病毒。抗原关系比较（r 观察到四种针对SAT2参考抗血清测试的2013/2014暴发病毒的高中和抗体滴度，这些抗体代表了从南非（异型I）和津巴布韦（异型II）的牛和水牛中分离出的病毒。抗原关系比较（r 观察到四种针对SAT2参考抗血清测试的2013/2014暴发病毒的高中和抗体滴度，这些病毒代表了从南非（拓扑I）和津巴布韦（拓扑II）的牛和水牛中分离出的病毒。抗原关系比较（r具有参考抗血清的暴发病毒的_1个值）表明疫苗匹配良好，r ₁值的90％> 0.3。对于三种南非疫苗/参考菌株，2013/2014年暴发病毒的r ₁值为0.4及以上。这些结果证实了SAT2病毒中存在遗传和抗原变异性，并暗示了南非野生动植物与牲畜交界处新变异的出现。应进行野外病毒的连续鉴定，以鉴定新的病毒株作为流行病学监测，以提高疫苗接种力度。